Xvive Headphone Amplifier Acoustic Amplug Amplifier Mini Amp USB Charge GA-1 Helps to deliver high-quality guitar sounds, retaining the original sound output of the guitar. Designed with 3 knobs: blend / tone / volume knob. AUX jack lets you connect an external audio device to this jack. Uses the headphone jack to connect headphone, portable speaker or mixer. Compact and light-weight design, not bigger than a hand of the adults.